Synthesis of some new bis-3,4-dihydropyrimidin-2(1H)-ones by using silica-supported tin chloride and titanium tetrachloride

Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing toluene.These solid acids have been employed as the catalysts for the synthesis of bisdihydropyrimidin -2(1H)-ones from aromatic dialdehydes,1,3-dicarbonyl compounds and urea at 90℃under solvent-free conditions.

Highly efficient synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by heteropoly acids in water

Heteropoly acids efficiently catalyzed the cyclocondensation reaction of anthranilamide with aldehydes in water at ambient temperature and afforded the corresponding 2,3-dihydro-4（1H）-quinazolinones compounds in good to excellent yields.This method provides mild reaction conditions and clean reaction profiles,using a small quantity of catalyst and a simple workup procedure.

H_3PMo_(12)O_(40) catalyzed three-component one-pot synthesis of 4,6-diarylpyrimidin-2(1H)-ones under solvent-free conditions

4,6-Diarylpyrimidin-2(1H)-one derivatives have been synthesized from three-component one-pot condensation of acetophe-none derivatives,aldehydes and urea in the presence of trimethylsilyl chloride and a catalytic amount of HPMoOunder solvent-free conditions.

Synthesis and Crystal Structure of 1-(4-Fluorophenyl)-2-hexylthiobenzo[4,5]-furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H)-one

The crystal structure of the title compound 1-（4-fluorophenyl） -2-hexylthio-benzo [4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5（1H） -one（C23H21FN4O2S,Mr = 436.5） has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic,space group P21/n with a = 13.9854（3） ,b = 17.2678（4） ,c = 18.1828（5）A,β = 99.364（2） °,V = 4332.58（18） A^3,Z = 4,Dc = 1.338,F（000） =1824,μ = 0.185 mm^-1,MoKa radiation（λ = 0.71073） ,R = 0.0538 and wR = 0.1162 for 4728 observed reflections with I 〉 2σ（I） . X-ray diffraction analysis reveals the fused rings of benzo[4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a] pyrimidin-5（1H） -one system are nearly coplanar. The crystal packing is mainly stabilized by weak intermolecular C-H···O hydrogen bond and π-π interactions.

Synthesis and Crystal Structure of a New Quinazolinone Compound 2,3-Dihydro-2-(2-hydroxyphenyl)-3-phenyl-quinazolin-4(1H)-one

A new quinazolinone compound 2,3-dihydro-2-(2-hydroxyphenyl)-3-phenyl- quinazolin-4(1H)-one 3 ([C20H16O2N2]?C2H5OH, Mr = 362.42) and compound 2-(2-hydroxy- benzylidene-amino)-N-phenyl-benzamide 2 (C20H16O2N2, Mr = 316.34) were prepared from a precursor of 2-amino-N-phenyl-benzamide 1 (C13H12ON2, Mr = 212.25). Compound 3 was characterized by single-crystal X-ray diffraction analysis. The crystal belongs to orthorhombic, space group Pbca with a = 1.2889(11), b = 1.6170(14), c = 1.7729(15) nm, V = 3.695(6) nm3, Z = 8, F(000) = 1536, Mr = 362.42, Dc = 1.303 g/cm3, μ(MoKα) = 0.087 mm-1, R = 0.0447 and wR = 0.0879. The crystal structure analysis indicates that the title compound has a two-dimensional network structure formed by hydrogen bonds and electrostatic interactions.

Synthesis and Characterization of a Novel Copoly(aryl ether ketone) Containing 4, 4'-Biphenyl-bis[4-phthalazin-1(2H)-one] Moiety

A new monomer of 4, 4-biphenyl-bis[4-phthalazin-1(2H)-one] was synthesized from biphenyl and phthalic anhydride, and a novel copoly(aryl ether ketone) (PPEK) was synthesized from 2, 2-bis(4-hydroxyphenyl)-propane (BPA), 4, 4'-biphenyl-bis-[4-phthalazin-1(2H)-one], 4, 4- difluorodiphenylketone (DFK). The monomer and copolymer were characterized by FT-IR and 1H-NMR. DSC and TGA were used to the novel polymer.

Synthesis and Crystal Structure of 4-Bromo-5-ethoxy-3-methyl-5- (naphthalen-1-yl)-1-tosyl-1H-pyrrol-2(5H)-one

The title compound 4-bromo-5-ethoxy-3-methyl-5-（naphthalen-l-yl）-l-tosyl-lH- pyrrol-2（5H）-one 1 （C24H22BrNO4S, Mr = 500.40） has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 8.8562（15）, b = 18.118（3）, c = 14.055（2）A, β = 99.855（3）^o, V= 2221.9（6）A3, Z = 4, Dc = 1.496 g/cm^3,μ= 1.975 mm^-1, 2 = 0.71073A, F（000） = 1024, R = 0.0607 and wR = 0.1371.

新型硫代试剂((二甲基氨基-亚甲基)氨基)-3H-1,2,4-二噻唑-3-硫酮的合成工艺研究

以四氢呋喃(THF)为溶剂,采用易得的5-氨基-1,2,4-二噻唑-3-硫酮(氢化黄原素)和N,N-二甲基甲酰胺二甲基缩醛为原料合成((二甲基氨基-亚甲基)氨基)-3 H-1,2,4-二噻唑-3-硫酮(DDTT)。通过对影响收率的关键因素进行研究,找到了最佳反应条件:n(氢化黄元素)∶n(N,N-二甲基甲酰胺二甲基缩醛)为1∶1.1,25℃下反应6h,收率达90%。合成工艺操作方便,纯化简单,收率高。

Melamine trisulfonic acid:A new,efficient and recyclable catalyst for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones in the absence of solvent

Melamine trisulfonic acid（MTSA） can be used as an efficient and recyclable catalyst for the promotion of the synthesis of 3,4- dihydropyrimidin-2（1H）-ones/thiones（DHPMs） in the absence of solvent.All reactions were performed at 80℃in good to high yields.

1－（1－H－苯并三唑－1－乙酰基）－4－苯甲酰基氨基硫脲及其噻二唑和三唑啉衍生物的合成

于固液相转移条件下，以ＰＥＧ－６００为相转移催化剂，通过苯并三唑与氯乙酸乙酯反应，合成了１－Ｈ－苯并三唑－１－乙酸乙酯（Ⅱ）．Ⅱ与８５％的水合肼反应，制得相应的酰肼（Ⅲ）．Ⅲ与苯甲酰基异硫氰酸酯反应，则得１－（１－Ｈ－苯并三唑－１－乙酰基）－４－苯甲酰基氨基硫脲（Ⅳ）．Ⅳ在酸或碱存在下环化，分别得到１，３，４－噻二唑（Ⅴ）和１，２，４－三唑啉－５－硫酮。

Three component reactions: An efficient and green synthesis of 3, 4-dihydropyrimidin-2-(1H)-ones and thiones using silica gel-supported L-pyrrolidine-2-carboxylic acid-4-hydrogen sulfate

An environmentally benign aqueous protocol for the synthesis of 3,4-dihydropyrimidin-2-（ 1 H）-ones and thiones promoted by a green catalyst, silica gel-supported L-pyrrolidine-2-carboxylic acid-4-hydrogen sulfate, has been developed. The use of nontoxic, thermally stable and inexpensive amino acid catalyst makes the process simple with minimal amount of chemical waste. Compared with classical Biginelli reaction conditions, this new method has the advantages of high yields and simple workup procedures.

Silica-bonded N-propyl sulfamic acid as an efficient recyclable catalyst for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones under heterogeneous conditions

Silica-bonded N-propyl sulfamic acid （SBNPSA） catalyzed one-pot three component Biginelli condensation of different substituted aromatic aldehydes with ethyl acetoacetate and urea/thoiurea to the respective 3,4-dihydropyrimidin-2-（lH）-ones and thiones in environment friendly procedure is described. The facile reaction conditions, simple isolation and purification procedures of this method make it a good option for the svnthesis of dihydropyrimidinones.

Sulfamic acid as a reusable and green catalyst for efficient and simple synthesis of 2-substituted-2,3-dihydroquinazolin-4(1H)-ones in water or methanol

A series of 2,3-dihydroquinazolin-4（1H）-ones have been synthesized in good to excellent yields through direct cyclocondensation of anthranilamide and aryl aldehydes or ketones in water or methanol under mild conditions.The reaction was efficiently promoted by 10 mol%sulfamic acid（SA,H_2NSO_3H） and the catalyst could be recovered easily after the reactions and reused without evident loss of reactivity.

Synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by zirconium(Ⅳ) chloride as a mild and efficient catalyst

2,3-Dihydroquinazolin-4（1H）-ones have been synthesized in the high to excellent yields via condensation of 2-aminobenzamide with aldehydes and ketones in the presence of catalytic amount of ZrCl_4 in EtOH at room temperature.Mild reaction conditions, clean reaction media,simple workup and easy purification are advantages of this methodology.

Strontium chloride-catalyzed one-pot synthesis of 2,3-dihydroquinazolin-4(1H)-ones in protic media

A wide range of mono-and disubstituted 2,3-dihydroquinazolin-4（1H）-ones were obtained in high yields by condensation of isatoic anhydride,aldehydes with ammonium salts or primary amines in the presence of strontium chloride in aqueous ethanol under reflux.

Synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by a-chymotrypsin

We discovered that a-chymotrypsin has a promiscuous ability to catalyze the cyclocondensation of aromatic and aliphatic aldehydes with 2-aminobenzamides to afford the corresponding 2,3-dihydroquinazolin-4（1H）-ones successfully in high yields（90%–98%） under alcohol solvent. The catalytic activity of a-chymotrypsin was evaluated through investigating the temperature, the enzyme loading and the ratio of substrates in the enzyme-catalyzed reactions. The present method proves to be efficient and environmentally friendly in terms of short reaction time, high yield, green catalyst and the clean products obtained without further purification processes.

布朗斯特酸性离子液体[DC2O2IM][p-CH3PhSO3]催化Biginelli三组分反应的研究

本文报道了布朗斯特酸性离子液体1,3-二羧甲基咪唑对甲苯磺酸盐作为一种绿色、环境友好的催化剂,成功地催化Biginelli三组分反应合成了一系列3,4-二氢嘧啶-2(1H)-酮或硫酮化合物。该方法具有条件温和、产率高、反应时间短的优点。此外,催化剂离子液体可循环使用五次且催化活性没有明显降低。

Catalytic activity of TiO_2 nanoparticles in the synthesis of some2,3-disubstituted dihydroquinazolin-4(1H)-ones

Green chemistry is playing an important role for synthesizing organic compounds, due to its eco-friendly nature and low cost. In green chemistry, metal nanoparticles exhibited some useful physical and chemical properties （catalytic activity）. Due to its diverse properties, nanoparticles can be utilized as a catalyst in various organic reactions. Recent research has been directed towards the utilization of eco- friendly and bio-friendly plant materials in nanoparticles synthesis. In our present work, TiO2 nanoparticles （TiO2 NPs） were synthesized using Annona squamosa peel extract and their catalytic applications were studied on the 2,3-disubstituted dihydroquinazolin-4（l1H）-one synthesis. Synthesized compounds were confirmed using FT-IR.1H NMR, 13C NMR and GC-MS analyses.

Copper(Ⅱ)-Catalyzed Synthesis of N-Substituted-3-amino-4- cyano-isoquinoline-1(2H)-ones by the Reaction of N-Substituted-2-iodobenzamides with Malononitrile

A novel Cu(OAc)_(2)•H_(2)O catalyzed coupling reaction of N-substituted-2-iodobenzamides with malononitrile to afford N-substituted-3-amino-4-cyano-isoquinoline-1(2H)-ones is described.The reaction proceeded in DMSO at 90℃ for 5 h in nitrogen without external ligands.

Design, Synthesis, and Evaluation of 3-（（4-（t-Butyl）-2-（2- benzylidenehydrazinyl）thiazol-5-yl）methyl）quinolin- 2（1H）-ones as Neuraminidase Inhibitors

A series of novel 3-（（4-（t-buty-）-2-（2-benzylidenehydrazinyl）thiazol-5-yl）methyl）quinolin-2（1H）-ones （7a--7z） were designed, synthesized and evaluated for their ability of inhibiting neuraminidase （NA） of influenza H1N1 virus. Some compounds displayed moderate influenza NA inhibitory activity. Compound 71 with the scaffold of 2-（2-（2-methoxybenzylidene）hydrazinyl）thiazole was the best one, exhibiting moderate NA inhibitory activity with ICs0 of 44.66 ~tmol/L. Structure-activity relationship showed that compounds with methoxy or hydroxy groups at the ortho position, fluorine and nitro groups at the meta position and chlorine and bromine groups at the para posi- tion of phenyl ring were more active. Docking study indicated that compound 71 has important interactions with some key residues （including Asp151, Glu119, Arg292, Tyr406, and Asn347） and binds to 430-cavity adjacent to NA active site.